SOLUTION: Find the solution of ach quadratic equations using the quadratic formula. 1. X^2 + 10x + 9 = 0 2. x^2 - 12x + 25 = 0 3. x^2 + 5x - 14 = 0 4. x^2 - 4x + 12 = 0 5. x^2 + 7x = 0

Algebra ->  Finance -> SOLUTION: Find the solution of ach quadratic equations using the quadratic formula. 1. X^2 + 10x + 9 = 0 2. x^2 - 12x + 25 = 0 3. x^2 + 5x - 14 = 0 4. x^2 - 4x + 12 = 0 5. x^2 + 7x = 0       Log On


   

Question 980878: Find the solution of ach quadratic equations using the quadratic formula.
1. X^2 + 10x + 9 = 0
2. x^2 - 12x + 25 = 0
3. x^2 + 5x - 14 = 0
4. x^2 - 4x + 12 = 0
5. x^2 + 7x = 0
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!
1.
x%5E2+%2B+10x+%2B+9+=+0
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
x+=+%28-10+%2B-+sqrt%28+10%5E2-4%2A1%2A9+%29%29%2F%282%2A1%29+
x+=+%28-10+%2B-+sqrt%28+100-36+%29%29%2F2+
x+=+%28-10+%2B-+sqrt%28+64+%29%29%2F2+
x+=+%28-10+%2B-+8%29%2F2+
solutions:
x+=+%28-10+%2B+8%29%2F2+
x+=+-2%2F2+
x+=+-1+
or
x+=+%28-10+-+8%29%2F2+
x+=+-18%2F2+
x+=+-9+

+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+x%5E2+%2B+10x+%2B+9+%29+


2.
x%5E2+-+12x+%2B+25+=+0
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
x+=+%28-%28-12%29+%2B-+sqrt%28+%28-12%29%5E2-4%2A1%2A25+%29%29%2F%282%2A1%29+
x+=+%2812+%2B-+sqrt%28+144-100+%29%29%2F2+
x+=+%2812+%2B-+sqrt%28+44+%29%29%2F2+
x+=+%2812+%2B-+6.63%29%2F2+
solutions:
x+=+%2812+%2B+6.63%29%2F2+
x+=+18.63%2F2+
x+=+9.3
or
x+=+%2812+-+6.63%29%2F2+
x+=+5.37%2F2+
x+=+2.7

+graph%28+600%2C+600%2C+-10%2C+15%2C+-10%2C+30%2C+x%5E2+-+12x+%2B+25+%29+

3.
x%5E2+%2B+5x+-+14+=+0
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
x+=+%28-5+%2B-+sqrt%28+5%5E2-4%2A1%2A%28-14%29+%29%29%2F%282%2A1%29+
x+=+%28-5+%2B-+sqrt%2825%2B56+%29%29%2F2+
x+=+%28-5+%2B-+sqrt%2881%29%29%2F2+
x+=+%28-5+%2B-+9%29%2F2+
solutions:
x+=+%28-5+%2B+9%29%2F2+
x+=+4%2F2+
x+=+2+
or
x+=+%28-5+-+9%29%2F2+
x+=+-14%2F2+
x+=+-7+

+graph%28+600%2C+600%2C+-10%2C+10%2C+-25%2C+15%2C+x%5E2+%2B+5x+-+14+%29+


4.
x%5E2+-+4x+%2B+12+=+0
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
x+=+%28-%28-4%29+%2B-+sqrt%28+%28-4%29%5E2-4%2A1%2A12+%29%29%2F%282%2A1%29+
x+=+%284+%2B-+sqrt%28+16-48+%29%29%2F2+
x+=+%284+%2B-+sqrt%28+-32+%29%29%2F2+
x+=+%284+%2B-+5.7i%29%2F2+
solutions:
x+=+%284+%2B+5.7i%29%2F2+
x+=+2+%2B+2.85i+
or
x+=+%284+-+5.7i%29%2F2+
x+=+2+-+2.85i+
no real solutions; so, there is no x-intercepts

+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+25%2C+x%5E2+-+4x+%2B+12++%29+


5.
x%5E2+%2B+7x+=+0
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
x+=+%28-7+%2B-+sqrt%28+7%5E2-4%2A1%2A0+%29%29%2F%282%2A1%29+
x+=+%28-7+%2B-+sqrt%28+49+%29%29%2F2+
x+=+%28-7+%2B-+7%29%2F2+
solutions:
x+=+%28-7+%2B+7%29%2F2+
x+=+0%2F2+
x+=+0+
or
x+=+%28-7+-+7%29%2F2+
x+=+-14%2F2+
x+=+-7+

+graph%28+600%2C+600%2C+-10%2C+10%2C+-20%2C+10%2C+x%5E2+%2B+7x+%29+